For example, in a transmission type liquid crystal projector system, light emitted from a light source is split into beams of red, green, and blue, the different color beams are modulated in accordance with image information or image signals by three light valves configured by liquid crystal display devices (hereinafter referred to as “LCD devices”), and the modulated color beams are combined and projected the same onto a projection surface in an enlarged image.
As a light valve mounted in a liquid crystal projector etc., generally, an active matrix drive type LCD device driven by thin film transistors (hereinafter referred to as TFTS), is used.
As an LCD device of an active matrix drive system, a twisted nematic (TN type) LCD device having a molecular alignment twisted by 90 degrees will be described.
In this TN type LCD device, as an optical modulation element, a TN type liquid crystal light valve is used. Optical modulation becomes possible by using an incident side polarizer and an emission side polarizer which are arranged so as to sandwich the light value.
The incident side polarizer and the emission side polarizer control the polarization direction of light incident upon the liquid crystal light valve and, at the same time, these polarizers control the polarization direction of the light beam emitted from the liquid crystal light valve.
The transmission type liquid crystal projector system explained above uses a twisted nematic (TN) mode as the liquid crystal mode of the liquid crystal device. In particular, in recent years, in order to achieve a higher luminance, a higher contrast, a higher definition, and a longer operable life, study of the use of a liquid crystal device operated in a vertical alignment (VA) mode has started (see for example Patent Documents 1 and 2).    Patent Document 1: Japanese Patent Publication (A) No. 2006-11298    Patent Document 2: Japanese Patent Publication (A) No. 2006-98669